1. Field of the Invention
This invention relates to a method and apparatus for weaving rod piercing type three-dimensional multiple-axis fabric.
2. DISCUSSION OF THE RELATED ART
In a co-pending prior application H2-91263, the present inventors proposed a weaving machine for rod piercing type three-dimensional multiple-axis fabric, in which three-dimensional fabric is woven by inserting a group of weft rods into a plural number of parallelly arranged warp rods from a plural number of directions. The weaving machine of this kind involves three problems as discussed below.
First, in a weaving machine for rod piercing type three-dimensional fabric, the fore ends of inserted weft rods are retained on a fall-preventive wall which prevents the weft rods from falling off. In step with the progress of a weaving operation, the fall-preventive wall is fed sequentially in the weaving direction along with a rod support plate, which supports a woven part of fabric and the warp rods, thereby forming three-dimensional fabric to a desired length.
However, a weaving machine, which is arranged to feed the fall-preventive wall along with woven fabric and rod support plate, requires the inserting weft rod group to have a length which is far longer than the length which is necessary for the fabric, as explained below with reference to FIG. 8.
More specifically, in a weaving process for three-dimensional four-axis fabric with a hexagonal shape in section as shown in FIGS. 8 to 10, in order to insert, from each of three arrowed directions, a group of flatly arrayed weft rods 2 into a group of warp rods 1 which are arranged vertically relative to the face of the drawing, it is necessary to secure an insertion space S for each weft rod group to be inserted by a rod insertion mechanism 15, and to provide a fall-preventive wall W for each one of the weft rod groups. For these purposes, the fall-preventive walls W, which need to have a width almost the same as the width of the insertion space S, have to be located at a relatively large distance from the warp rod group 1, and, in order to abut the fore ends of the weft rod groups against the fall-preventive walls W, the weft rods are required to have a length far longer than the length which is needed for weaving the three-dimensional fabric, as indicated at L in the same figure.
Thus, in case of a rod piercing type three-dimensional multiple-axis fabric weaving machine which is arranged to move the fall-preventive walls W up and down together with the woven fabric for the purpose of retaining the fabric in a stabilized state, wastefully lengthy weft rods are needed because of the layout of the rod insertion means which has to be located in such a way as to evade the fall-preventive walls, and there is a necessity for considering a countermeasure to this problem.
The second problem concerns the beating operation in the weaving process of three-dimensional fabrics having four axes or more.
A rod piercing type three-dimensional three-axis fabric can be woven by inserting weft rods into a large number of parallelly disposed warp rods from two perpendicularly intersecting directions. In a weaving machine for such three-dimensional three-axis fabric, the inserting weft rods are arrayed in parallel relation with each other, so that it is possible to beat the inserted weft rods successively by means of a beater with a large number of holes for threading the weft rods therethrough.
However, in case of three-dimensional fabric of four or more axes as shown in FIGS. 1, 9 and 10, the weft rod groups, to be inserted into a group of warp rods from a plural number of directions, are not disposed in parallel relation with each other and are projected with complicated inclinations which make the beating operation as mentioned above difficult. Therefore, a suitable beating means needs to be developed in order to weave a three-dimensional fabric by insertion of weft rods which are arrayed in high density.
The third problem concerns the arrangement of the weft rods to be inserted.
In this connection, the present inventors made a proposal in their copending prior application H2-99659 with regard to three-dimensional multiple-axis fabric woven from matrix-bound roving rods which are arranged in the directions of the respective axes.
In case of the rod piercing type three-dimensional fabric of this sort, more specifically, of the three-axis fabric having the respective rod groups disposed in perpendicularly intersecting relation with each other, it is possible to insert the two perpendicularly intersecting weft rod groups, each arrayed flatly in one plane, alternately group by group into a large number of parallelly disposed rods of the warp group.
However, the insertion of flatly arrayed weft rods is difficult in case of a three-dimensional fabric of four axes or more.
More specifically, referring to FIGS. 9 and 10 which show the construction of a three-dimensional four-axis fabric, and particularly to FIG. 10 which shows a three-dimensional four-axis fabric 50 being formed by inserting inclined weft rod groups 2 into a parallelly disposed weft rod group 1 from three different directions, seen in the direction of insertion of one of the weft rod groups 2. As seen in that figure, the rods 2A, 2B, 2C, 2D and 2E or the rods 2A, 2B, 2C', 2D' and 2E' of the weft rod group 2, which is inserted into the warp rod group 1 from one direction in a cycle of weaving operation, are disposed in a complicated inclined plane P.sub.3 relative to a number of parallel planes P.sub.1 and P.sub.2 which are located in slightly deviated positions along the warp rod group 1 in the weaving direction or relative to the warp rod group 1. Accordingly, if the rods of the weft rod group 2 were to be inserted into the warp rod group 1 simultaneously from one direction in one cycle of weaving operation, it would become necessary for the weaving machine to employ a weft rod insertion mechanism which is adapted to support the inserted weft rods respectively on surfaces of different levels and to array the weft rods on a surface in a complicated inclined state before insertion, resulting in complication in construction and fabrication process of the weft rod insertion mechanism.
In conventional arrangements such as disclosed in, for example, U.S. Pat. No. 5,076,330, a reed is not rotated if it is provided with a plurality of weft rod inserters (see column 9, lines 5-13 of U.S. Pat. No. 5,076,330). In the present invention, a weft rod inserter is provided for each direction of weft rod insertion, and components for warp rod insertion are not rotated around a vertical axis.